A U.S. textbook publisher said Friday it "unequivocally" stands by the description of Japan's sexual enslavement of women during World War II in one of its books after Japan's government asked for changes in it.

Japan made the request to the publisher, McGraw-Hill, last month, claiming there are grave errors and descriptions in the book, "Tradition & Encounters: A Global Perspective on the Past," which it said conflict with the country's stance on the sexual slavery issue.

The request was seen as an attempt to water down the atrocity.

Recently, representatives from the Japanese government and others have reached out to McGraw-Hill Education asking the company to change the description of 'comfort women' in one of our publications," the company said in a statement sent to Yonhap News Agency.

Comfort women' is a euphemistic term for sex slaves.

"Scholars are aligned behind the historical fact of 'comfort women' and we unequivocally stand behind the writing, research and presentation of our authors," it said.

Earlier this week, Japanese Prime Minister Shinzo Abe told a parliamentary meeting that he was surprised to learn how the McGraw-Hill book describes the sexual slavery issue, and pledged government efforts to continue to push for changes.

The sexual slavery issue has been the biggest thorn in frayed relations between Japan and South Korea, with Seoul demanding Japan take steps to address the grievances of elderly Korean victims of the atrocity and Japan refusing to do so.

Historians estimate that up to 200,000 women, mainly from Korea, which was a Japanese colony from 1910 to 1945, were forced to work in front-line brothels for Japanese soldiers during World War II. But Japan has been accused of attempting to whitewash the atrocity.

(Yonhap)